The potential of seep carbonates to preserve the seawater isotope compositions
The isotopic compositions of authigenic minerals of marine sediments are potential proxies for reconstructing paleoenvironmental conditions. However, the reliability and applicability of this tracer remain elusive due to the limited spatial distribution scope and alteration during early diagenesis. Here we report isotopic measurements of seep carbonates (calcium, molybdenum, strontium, neodymium) generated by gas hydrate dissociation, sampled from a core drilled at the South China Sea. Our results show that there is approximately −1.2‰ calcium isotopic fractionation between aragonite and seawater. On the other hand, the molybdenum, strontium, and neodymium isotopic compositions are similar to those found in modern seawater. These results indicate that aragonite-dominated seep carbonate, which preferentially precipitates in proximity to the seawater-sediment interface, can preserve the pristine seawater isotopic signatures. Therefore, we infer that aragonite-dominant seep carbonate is a promising archive for coeval seawater chemistry. Aragonite-dominated seep carbonates are a promising archive for understanding past seawater chemistry changes, according to an isotopic analysis of a core from the South China Sea.
Authors
- Xuexiao Jiang
- Ganglan Zhang (ORCID: https://orcid.org/0000-0001-6318-2794)
- Yinan Deng (ORCID: https://orcid.org/0000-0003-4061-9767)
- Fang Chen (ORCID: https://orcid.org/0000-0002-7616-7224)
- Qingjun Guo (ORCID: https://orcid.org/0000-0003-1538-1339)
- Hongfei Lai (ORCID: https://orcid.org/0000-0002-3387-0075)
- Daohua Chen
- Zenggui Kuang (ORCID: https://orcid.org/0000-0002-1019-5863)
- Dawuda Usman
- Bin Zhao (ORCID: https://orcid.org/0000-0002-8167-3260)
- Yufei Liu (ORCID: https://orcid.org/0000-0003-1423-6228)
- Jun Cao
- Gaowen He (ORCID: https://orcid.org/0000-0002-8773-6701)
- Shengxiong Yang (ORCID: https://orcid.org/0000-0002-8706-5741)
- Yunxin Fang (ORCID: https://orcid.org/0000-0001-8902-919X)
- Mingyu Zhao (ORCID: https://orcid.org/0009-0003-3931-1789)
- Yangtao Zhu
Institutions
- Chinese Academy of Sciences (CN)
- Ministry of Natural Resources (CN)
- China Geological Survey (CN)
- Guangzhou Marine Geological Survey (CN)
- Institute of Geology and Geophysics (CN)
- Institute of Geographic Sciences and Natural Resources Research (CN)
- University of Chinese Academy of Sciences (CN)
Publication Details
- Journal
- Communications Earth & Environment
- Published
- 2025-05-23
- DOI
- https://doi.org/10.1038/s43247-025-02388-w
- Citations
- 4
- Primary Topic
- Methane Hydrates and Related Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 3.44
Funders
- National Natural Science Foundation of China
- Basic and Applied Basic Research Foundation of Guangdong Province